1. Field of the Invention
The present invention relates to compositions and methods that increase the rate at which a wound will heal.
2. Description of Related Art
Glycosaminoglycans (GAGs) are polysaccharides found in vertebrate and invertebrate animals. Several GAGs have been found in tissues and fluids of vertebrate animals. The known GAGS are chondroitin sulfate, keratan sulfate, dermatan sulfate, hyaluronic acid, heparin and heparan sulfate.
Chondroitin sulfate is a linear polymer occurring in several isomers, named for location of the sulfate group. Chondroitin-4 sulfate is found in nasal and tracheal cartilages of bovines and porcines. It is also found in the bones, flesh, blood, skin, umbilical cord, and urine of these animals. Chondroitin-6 sulfate has been isolated from the skin, umbilical cord, and cardiac valves of these animals. Chondroitin-6 sulfate has the same composition, but slightly different physical properties from chondroitin-4 sulfate. These are the most common isomers used in the present invention. The polymer is also known as chondroitin polysulfate sodium, chondron, sodium chondroitin poly sulfate, and sodium chondroitin sulfate. For consistency, the term "chondroitin sulfate" will be used for all chondroitin sulfate isomers throughout this application. Chondroitin sulfate is involved in the binding of collagen and is also directly involved in the retention of moisture. These are both properties that aid the healing process.
Open wounds on the skin are a potential gateway for infection to enter the body. The skin is an exterior protective barrier to outside contaminants. When the skin is damaged, with an open breach, these contaminants are free to enter the body. Once inside the body, these contaminants may have effects of varying degree, but almost always become more difficult to treat and slow the healing process of the original wound.
Just as nature has provided the skin as a barrier for protection, it has also provided mechanisms for repair of the skin. Depending upon the nature of the injury, this repair process may take hours, days, months, or even years. Many factors determine the length of time it takes to heal. That pathogenic contaminants may enter the body through the wound until the skin's integrity is restored, however, is certain. For this reason, it is desirable to heal open wounds as quickly as possible.
To fight infection, wound management traditionally involves an initial cleansing of the affected area to remove any contaminants such as dirt, clothing particles, or other debris. Damaged materials or tissues are removed when necessary, and antiseptic agents applied to sterilize the area. Sterile dressings are often applied, and periodically changed, to keep the area as clean and sterile as possible. Complex biological mechanisms occur during the healing process. During the process, chemical signals call fibroblasts to the wound site, ultimately generating connective structures mainly of collagen. Endothelial cells generate new blood capillaries that feed the new growth. The cell growth continues until the wound is filled, forming permanent new tissue.
Because shortened periods of healing mean shortened exposure time, it would be beneficial to have open wounds heal as quickly as possible. Likewise, it would be beneficial if a medical practitioner could apply a product, using the healing advantages of chondroitin sulfate and other GAGs, to an open wound to speed the healing process.
Chondroitin sulfate, and other GAGs, used to aid healing or trauma have been the subject of previous patents. U.S. Pat. No. 4,808,570, which issued to Michaeli on Feb. 28, 1989, discloses compositions and method for improving wound healing that uses GAGs, but teaches against the use of chondroitin sulfate. U.S. Pat. No. 4,640,912, issued to Hausman on Feb. 3, 1987, discloses the use of "active" chondroitin sulfate A and "active" chondroitin sulfate C to prevent cancer cell implantation, bacterial infestation, trauma, irritation or damage from foreign instruments in the kidney, renal pelvis, ureter, bladder, urethra, etc. by irrigation with a solution containing the chondroitin sulfate.
U.S. Pat. No. 4,863,907, which issued to Sakurai, et al. on Sep. 5, 1989, discloses cross-linked glycosaminoglycans and their use. The patent discloses cross-linked glycosaminoglycans, with a cross-linking index of 0.05 or more per mole, for various medical and cosmetic uses.
U.S. Pat. No. 5,366,964, which issued to Lindstrom, et al. on Nov. 22, 1994, discloses a viscoelastic solution. The solution contains 0.01-10% chondroitin sulfate and 0.01-10% sodium hyaluronate among other ingredients for use in ocular and surgical applications.
U.S. Pat. No. 4,983,580, which issued to Gibson on Jan. 8, 1991, discloses methods and materials for use in corneal wound healing. A preferred embodiment includes fibronectin and chondroitin sulfate in a corneal mortar composition.
U.S. Pat. No. 5,498,606, which issued to Soll et al. on Mar. 12, 1996, discloses a method of protecting human and animal cells. According to the patent, an intra-articular injection of a compound containing 40-55% by weight chondroitin sulfate is used in protecting cells.
U.S. Pat. No. 5,399,351, which issued to Leshchiner, et. al. on Mar. 21, 1995, discloses the preparation and use of biocompatible viscoelastic gel slurries. According to this invention, a gel containing cross-linked glycosaminoglycans for controlling adhesion formation between tissues resulting from surgical intervention.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus a wound treatment using chondroitin sulfate solving the aforementioned problems is desired.